*,
*::after,
*::before {
  box-sizing: border-box;
}
html {
  background-color: #efefef;
  min-height: 100%;
  font-size: 14px;
  color: #333;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}
body {
  margin: 0 auto;
  min-height: 100%;
  position: relative;
  text-align: center;
}

nav {
  width: 140px;
  padding: 12px 0;
  vertical-align: top;
  position: sticky;
  display: inline-block;
  top: 0;
  text-align: left;
}
.menu {
  list-style: none;
  margin: 0;
  padding: 0;
  color: #666;

  li {
    padding: 4px;
    transition: all 0.3s;
    > .menu {
      margin-left: 12px;
      display: none;
    }
    &:link {
      color: red !important;
    }
    a {
      display: block;
      text-decoration: none;
      color: inherit;
    }
    &.active {
      color: #4e6ef2;
      & > .menu {
        display: block !important;
      }
    }
  }
}

.app {
  &-root {
    display: inline-block;
    background-color: #fff;
    flex: 1;
    padding: 12px;
    width: 1000px;
    text-align: left;
    canvas {
      border: solid 1px #eee;
      border-radius: 5px;
      box-shadow: 0 0 10px rgba(0, 0, 0, 0.1) inset;
    }
    section[id] {
      margin-bottom: 24px;
      padding-bottom: 24px;
      border-bottom: dashed 1px #eee;
      p {
        color: #666;
        code {
          background-color: darken(#fff, 5);
          border: solid 1px darken(#fff, 15);
          border-radius: 5px;
          padding: 0 5px;
          margin: 0 4px;
        }
      }
    }
  }
}
pre {
  margin: 0;
}
.d-flex {
  display: flex;
  gap: 12px;
  &__item {
    flex: 1;
  }
}

.demo-block {
  margin-bottom: 60px;
  &-code {
    width: 0;
  }
}
